Improvement in try-square and bevel



UNITED STATES PATninTQjTFIoE.

ISAIAH J. ROBINSON, OF ST. JOHNSBURY, VERMONT.

IMPROVEMENT IN TRY-SQUARE AND BEVEL.

Specification forming part of Letters Patent No. 104,206, dated .lune 14, 1870.

To alt lwhom it may concern:

Beit known that I, IsAIAH J. ROBINSON, of St. Johnsbury, in the county of Caledonia and State of Vermont, have invented a new and Improved Bevel-Square; and I do hereby decl are that the following is a full and exact description of the same, reference being had to the accompanying drawing, and to the letters of reference marked thereon.

This invention has for its object the production ot' an improved bevel-square, so constructcil that its blade may be readily fixed and securely held in any desired position; and to that end it consists, mainly, in the employment of a wedge-shaped bar or its equivalent within the handle, which is operated by means ot' a thumb-screw in such manner as to press upon the blade or free itself from it.

In the drawing, Figure l represents a side elevation of my improved square; Fig. 2, a central vertical section.

To enable others skilled in the art to make and use my invention, I will now proceed to describe fully its operation and construction.

A represents the slotted plate of a bevelsquare, which is constructed in the usual manner. B represents the handle or body of the square, which is made in two parts, b b, as shown. One of these parts is suitably socketed for the reception of the bar O. The front ofthe socket is inclined upward, as shown in Fig. 2, and the front end of the bar corresponds also in shape with it, the arrangement being such that when the bar is thrust forward the incline of the socket will force it above the surface-line of the part b, in which it rests.

The bar O is necessarily made somewhat shorter than the body of the square. lts rear end is provided with a shoulder having a threaded orifice, in which moves the front end of the thumb-screw D. This latter is confined by shoulders d d to the rear end of the body of the square.

The operation will be readily understood.

By simply turning the thumb-screw the bar O is adjusted backward or forward at will. By moving it forward its front end is forced outward by means of the inclined socket, and it thus presses upon the blade and securely holds it in the position in which it may be fixed.

It' desired, a cam or other mechanical equivalent may be used in place of the wedge-shaped bar.

A simple tool is produced by this construction, which is easily operated and cannot readily get out of order.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The device described, consisting ofthe blade A, body B, bar O, and thumb-screw D, when combined as described, for the purpose set forth.

This specieation signed and witnessed this 22d day of November, 1869.

I. J. ROBINSON.

- Witnesses:

W. A. PIERCE, C. C. BURKE. 

